What layout constraint is this talking about? - ios

I've read all the SO questions that are similar to this and I'm so lost. I'm getting the following error:
2015-09-14 22:59:40.455 guess-who[60143:9602686] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7c0f8e30 UIImageView:0x7b6efb60.top == _UILayoutGuide:0x7c0f67a0.top>",
"<_UILayoutSupportConstraint:0x7c0f8ae0 V:[_UILayoutGuide:0x7c0f67a0(0)]>",
"<_UILayoutSupportConstraint:0x7c0f0070 _UILayoutGuide:0x7c0f67a0.bottom == UIView:0x7c0f65e0.bottom>",
"<NSAutoresizingMaskLayoutConstraint:0x7b6f6130 h=--& v=--& UIImageView:0x7b6efb60.midY == + 204>",
"<NSAutoresizingMaskLayoutConstraint:0x7b6f6160 h=--& v=--& V:[UIImageView:0x7b6efb60(220)]>",
"<NSLayoutConstraint:0x7b6f6dc0 'UIView-Encapsulated-Layout-Height' V:[UIView:0x7c0f65e0(518)]>",
"<NSAutoresizingMaskLayoutConstraint:0x7b6f6e20 h=-&- v=-&- 'UIView-Encapsulated-Layout-Top' V:|-(0)-[UIView:0x7c0f65e0] (Names: '|':UIView:0x7c0effc0 )>"
)
Will attempt to recover by breaking constraint
<_UILayoutSupportConstraint:0x7c0f0070 _UILayoutGuide:0x7c0f67a0.bottom == UIView:0x7c0f65e0.bottom>
I've gotten this for a bunch of other constraints which I've successfully solved, but this one is stumping me. I don't know what a UILayoutSupportConstraint is; the documentation is not very thorough. I've looked through the view debugger and UIView:0x7c0f65e0 seems to refer to my main view (although it's the child of a blank view, for some reason?). I'm not able to find anything with 0x7c0f67a0, although that seems to refer to the LayoutGuide, saying their bottoms must be equal. I'm not sure what other tools are available for me to use to figure this out.
EDIT:
Using the View Debugger, I've narrowed it down to one of these two constraints, neither of which I know the source of:
I can't find where either of these gets set. I know everyone's first suggestion is to set translatesAutoresizingMaskIntoConstraints to false, but that destroys my entire layout and I don't know how to fix it.

You could also consider adding accessibility identifiers and constraint identifiers to your views to make your AL logs more legible:
constraintVariableName.identifier = “constraintVariableName”;
In InterfaceBuilder, use the identifier property in the inspector.
self.loginButton.accessibilityLabel = NSLocalizedString("LoginButtonAccessibilityLabel", #"");
These id's will end up in the logs, such as you posted above, replacing things like UIView, UIImageView and UIConstraint with the ids.

It seems you have given constraints to image view with relation to Superview. So to satisfy you constraint of UILayoutGuide.bottom your constraints are broken. As you have added more or unnecessary constraints which were not required.
Constraints which are getting broken are:
UILayoutGuide.top = UIView.top
UILayoutGuide.height = 0
UILayoutGuide.bottom = UIView.bottom
UIImageView Height constraint
UIImageView Y position
UIView Height constraint
You have given UIView vertical spacing from top is '0' but missing bottom/height constraint.
Try changing the priority of height constraints from 1000 to 750 for UIImageview with height(220),UIView with height(518).
Also you need to check for bottom constraint for
"<NSAutoresizingMaskLayoutConstraint:0x7b6f6e20 h=-&- v=-&- 'UIView-Encapsulated-Layout-Top' V:|-(0)-[UIView:0x7c0f65e0] (Names: '|':UIView:0x7c0effc0 )>"
If it is possible then please attach demo on git for better idea.
Hope it helps.

Disabling translatesAutoresizingMaskIntoConstraints wrecks your layout because some of your stacked elements have no explicit height/width set (PlayAgain, cat, frame) and are based off the image contents.
Your example project isn't runnable out of the box, so I can't inspect the runtime layout. However, I'd start by specifying the height of those elements so there are fewer auto constraints. It also looks like you're changing a lot of the constraints at runtime, so you need to be cautious about altering constraints that will conflict with each other. Make sure that the layout's happy before you start constraint-constant fiddling!

Use this following Line. It may be help you.
[view setTranslatesAutoresizingMaskIntoConstraints:NO];

Related

Autolayout Issues in iOS 7 in Custom TableViewCell

I'm having issues with an Autolayout custom TableViewCell in iOS 7. The cell appears to display correctly, but I get a good deal of debugging console output, such as the following:
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property
translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x7f9c1a4b8500 V:[UILabel:0x7f9c1a4b72d0]-(0)-[UILabel:0x7f9c1a4b7680]>",
"<NSLayoutConstraint:0x7f9c1a4b8550 V:[UILabel:0x7f9c1a4b7680]-(0)-[UILabel:0x7f9c1a488910]>",
"<NSLayoutConstraint:0x7f9c1a4b85c0 V:[UILabel:0x7f9c1a488910]-(NSSpace(20))-| (Names: '|':UITableViewCellContentView:0x7f9c1a4b66d0 )>",
"<NSLayoutConstraint:0x7f9c1a4b87f0 V:|-(NSSpace(20))-[UILabel:0x7f9c1a4b6f00] (Names: '|':UITableViewCellContentView:0x7f9c1a4b66d0 )>",
"<NSLayoutConstraint:0x7f9c1a4b8840 V:[UILabel:0x7f9c1a4b6f00]-(NSSpace(8))-[UILabel:0x7f9c1a4b72d0]>",
"<NSAutoresizingMaskLayoutConstraint:0x7f9c1a4a70e0 h=--& v=--& V:[UITableViewCellContentView:0x7f9c1a4b66d0(44)]>"
)
I only get this output in iOS 7, and I see it on all of my custom table view cells, across multiple view controllers. I have followed all of the steps in this post:(Using Auto Layout in UITableView for dynamic cell layouts & variable row heights). I have tried adjusting the AutoresizingMask of the content view in these cells, but it does not stop these errors from appearing. I would greatly appreciate some advice on fixing these errors. Thanks!
The last one,
"NSAutoresizingMaskLayoutConstraint:0x7f9c1a4a70e0 h=--& v=--& V:[UITableViewCellContentView:0x7f9c1a4b66d0(44)]"
could indicate that in the tableviewcell the translatesAutoresizingMaskIntoConstraints property is set to YES. If this is the case try to set it to NO to avoid conflicts between your constraints and the automatic ones.
This means that you have constraints that conflict, and it is picking to satisfy one since they cannot all be satisfied.
Usually this means that you either have:
1)Constraints you know will not be satisfied simultaneously such as a minimum size or offset combined with a percentage or ratio. In this case all you need to do is reduce the priority of the one you want to break first.
Or, 2) duplicate constraints worded differently(center vertically, but also trailing space, etc) this one is harder for me to remotely diagnose, so posting the constraint would be important.
If the particular constraints are not that important to you (AKA you didn't spend that long adding them) then removing them all, adding suggested, and working from there is a very valid starting point.

Contraints greyed-out in Xcode

I am trying to debug+understand autolayout constraints and I notice that when debugging the view with xcode (using the cool layer thing) I noticed that on one element in the view the constraints look like this
and the view is indeed ignoring these constraints.
All constraints have the same priority (1000) since I want them all. All constraints were made with interface builder and not through code, and there are not warning or conflicts in IB.
But in runtime I do see this
Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x79684f10 V:[UIImageView:0x79686800(>=160)]>",
"<NSLayoutConstraint:0x7968a310 V:[UIImageView:0x79686800]-(130.5)-| (Names: '|':UIView:0x79686790 )>",
"<NSLayoutConstraint:0x7968a340 V:|-(0)-[UIImageView:0x79686800] (Names: '|':UIView:0x79686790 )>",
"<NSLayoutConstraint:0x796997b0 'UIView-Encapsulated-Layout-Height' V:[CoverCell:0x79686570(192)]>",
"<NSAutoresizingMaskLayoutConstraint:0x7969cd30 h=-&- v=-&- UIView:0x79686790.height == CoverCell:0x79686570.height>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x79684f10 V:[UIImageView:0x79686800(>=160)]>
So from this I understand that some rules conflict, but I'm not sure how to read this
the >=160 is a rule on the UIImageView so it would have height of atleast 160 and 130.5 is the bottom padding of the imageview (so when using systemLayoutSizeFittingSize:UILayoutFittingCompressedSize the height won't be 0. So the minimum height for the entire cell is 160+130.5)
The rest of the error I don't understand.
What is wrong with the constraints and why do constraint conflicts occur in runtime and not in IB?
XCode 6 now supports different layouts. This greyed out constraints exist in Compact Width | Any Height layout, for example, but you currently editing Any Width | Any Height.
More detailed:
Storyboard View Elements Greyed Out
It depends. If you don't use size classes the grey ones are the removed ones. And you need to remove them second time. No matter how stupid it sounds.
If you use size classes, it means that your current size class is different than for greyed constraint. (however the first scenario is also possible...)
In your case it looks like this is the first case. You need to remove greyed constraints once again.

Autolayout contraint error

So this autolayout error. Which I know why it is there but I am not sure how can I fix it. As with error its clear that its not able to resolve the constraints.
In portrait mode all 47 episode are listed and can be scrolled to. But in landscape mode it cant, which is clear as height of table is not changing thats way its is still down there but can't scroll to it.
So this is how I have setup.
Where as view controller has two view which works as placeholder upper is of for iAds and lower is holding table view. Idea was behind this. if ad is not loaded I will set height of View to zero which holds iADBanner. So that Table view takes up all space. (Got this idea from Ray Wenderlich's app level me up.) I was struggling with auto layout initially but I made it right so that view are taking up all width when sim goes to portrait mode. but somehow I am not able to fix the height of view which holds tableView.
Below are the screenshot of constraints.
I tried to be as descriptive as I can. but I am looking for more than just answer. I want to get to know this completely so that I will most likely won't have problem in future. I have finished raywenderlich tutorial already. So Any other pointer would be very much appreciate along with the answer.
2014-07-30 21:40:37.326 Test[85608:60b] Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) (
"<NSLayoutConstraint:0xa5afbc0 UIView:0xa69b7d0.width == 0.682303*UIView:0xa69b830.height>",
"<NSLayoutConstraint:0xa5afc80 V:|-(50)-[UIView:0xa69b830] (Names: '|':UIView:0xa69b7d0 )>",
"<NSLayoutConstraint:0xa5afdc0 V:[UIView:0xa69b830]-(0)-[_UILayoutGuide:0xa5a8410]>",
"<_UILayoutSupportConstraint:0xa5a7d20 V:[_UILayoutGuide:0xa5a8410(0)]>",
"<_UILayoutSupportConstraint:0xa5af490 _UILayoutGuide:0xa5a8410.bottom == UIView:0xa69b7d0.bottom>",
"<NSAutoresizingMaskLayoutConstraint:0xa792d10 h=--& v=--& H:[UIView:0xa69b7d0(480)]>",
"<NSAutoresizingMaskLayoutConstraint:0xa792dd0 h=--& v=--& V:[UIView:0xa69b7d0(271)]>" )
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0xa5afdc0 V:[UIView:0xa69b830]-(0)-[_UILayoutGuide:0xa5a8410]>
Break on objc_exception_throw to catch this in the debugger. The
methods in the UIConstraintBasedLayoutDebugging category on UIView
listed in <UIKit/UIView.h> may also be helpful.
The list of constraints in the error log is the key to understanding this type of problem. What you want to do is look at it carefully to correlate which lines refer to which constraints in your code/ui builder, and which hexadecimal address refers to which view.
V:[UIView:0xa69b830]-(0)-[_UILayoutGuide:0xa5a8410] is a constraint setting the bottom of a UIView to a layout guide, so most likely that's the last constraint in your screenshot "Vertical Space - Bottom layout guide - TableVi..." (presumably that's TableViewHolder truncated). That means UIView:0xa69b830 is your TableViewHolder.
V:|-(50)-[UIView:0xa69b830] (Names: '|':UIView:0xa69b7d0 ) is the constraint tying the top of TableViewHolder 50px from its superview, which must be UIView:0xa69b7d0.
UIView:0xa69b7d0.width == 0.682303*UIView:0xa69b830.height looks like an aspect ratio constraint between the superview width and the TableViewHolder height.
h=--& v=--& H:[UIView:0xa69b7d0(480)] and h=--& v=--& V:[UIView:0xa69b7d0(271)] are constraints on the superview that's derived from its autoresizingMask, where the width=480px, height=271px, and their top/left/width/height are fixed (based on h=--& v=--&). This is sort of the standard setup for the root view of a view controller — it's dimensions are managed manually by the view controller to fill the screen.
So once you have all that, you can see what the problem is: the superview has fixed dimensions 480x271. Meanwhile, TableViewHolder's height is being dictated by multiple conflicting constraints:
#1 and #2 are trying to stretch it vertically to fill its superview with a 50px margin at the top, so height = 271-50 = 221px.
#3 is trying to set the height as a ratio of the superview's width: height = 480/0.6823 = 703.5px
221 != 730.5!
Something's gotta give, and the OS just happened to pick #1, so the bottom of TableViewHolder extends past the bottom of the layout guide, making it stick out past the edge of the screen and inaccessible.
Your fix will likely involve getting rid of that aspect ratio constraint, but there might be other issues that appear once you fix that. Good luck!

iOS: Unable to simultaneously satisfy constraints

I've seen the common response to this question of not having constraints set up properly. However, I've worked through all of the ambiguities in Interface Builder, and all constraints seem OK. I'm not sure what to check next. I can't even tell where it is coming from. I'm not setting any constraints in code.
What can I do to figure out where it is coming form?
What can be the cause if Interface Builder doesn't report any ambiguities?
Here's the specific error:
2014-06-28 19:54:36.070 Prayer Feed[4497:60b] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x178290360 H:[UIImageView:0x13ee32490(20)]>",
"<NSLayoutConstraint:0x1782904f0 UITableViewCellContentView:0x178166840.centerX == UIImageView:0x13ee32490.centerX + 62>",
"<NSLayoutConstraint:0x178290540 H:|-(52)-[UIImageView:0x13ee32490] (Names: '|':UITableViewCellContentView:0x178166840 )>",
"<NSAutoresizingMaskLayoutConstraint:0x170286d60 h=--& v=--& H:[UITableViewCellContentView:0x178166840(247)]>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x178290360 H:[UIImageView:0x13ee32490(20)]>
I know the two place in code where I have a UIImageView constrained to 20x20, but again, IB tells me everything is fine.
This is the part where the problem is:
<NSAutoresizingMaskLayoutConstraint:0x170286d60 h=--& v=--& H:[UITableViewCellContentView:0x178166840(247)]>
This mask needs to be turned off.
I think that mask is off by default for IB elements that have constraints. So I assume you made something in code. You can turn it off in code like this:
contentView.translatesAutoresizingMaskIntoConstraints = NO
If this is really all IB only then I would like to know what code you use around creating table cells.

Unable to simultaneously satisfy constraints - No constraints in place

I have gone through and removed every single user constraint yet I am still getting the following error ONLY after I rotate the device. I have absolutely no clue why though. Does anyone have any ideas?
2013-01-14 21:30:31.363 myApp[35869:c07] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSAutoresizingMaskLayoutConstraint:0x84543d0 h=--& v=--& V:[UIView:0xa330270(768)]>",
"<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>",
"<NSLayoutConstraint:0xa338390 V:|-(841)-[UIView:0xa331260] (Names: '|':UIView:0xa330270 )>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>
Break on objc_exception_throw to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
Let's look at these one by one.
"<NSAutoresizingMaskLayoutConstraint:0x84543d0 h=--& v=--& V:[UIView:0xa330270(768)]>"
This is saying view 0xa330270 (A) must be 768 points high.
"<NSLayoutConstraint:0xa338350 V:[UIView:0xa331260]-(-1)-| (Names: '|':UIView:0xa330270 )>"
This is saying view 0xa331260 (B)'s bottom edge must be a gap of -1 from the bottom of A, which is it's superview.
"<NSLayoutConstraint:0xa338390 V:|-(841)-[UIView:0xa331260] (Names: '|':UIView:0xa330270 )>"
This is saying that B's top edge must be a gap of 841 points from the top of its superview, A.
These three things can't all be true - A can't be 768 points high, and contain a subview with a top edge 841 points inset from the top and -1 points inset from the bottom. Where have you defined each of these constraints?
You haven't said what layout you are trying to achieve, but it looks like you might have an autoresizing mask on the superview that is preventing it changing in height when you rotate the device. As far as I know the autoresizing constraints only appear if you have added views programmatically, since a storyboard or xib is either all-autolayout, or not. Unless you are doing something like adding an auto laid out view (loaded from a nib?) to another view from a non-autolayout nib?
Its worth knowing the basics, and understand what Apple/Xcode is trying to tell you through the logs
H = Horizontal constraint(for leading and Trailing)
V = Vertical constraint(top and bottom edge)
h = height
w = width
TopEdge -> V:|-(points)-[VIEW:memoryAddress]
BottomEdge -> V:[VIEW:memoryAddress]-(points)-|
Leading -> H:|-(points)-[VIEW:memoryAddress]
Trailing -> H:[VIEW:memoryAddress] -(points)-|
height -> h= --& v=--& V:[VIEW:memoryAddress((points)]
width -> VIEW:memoryAddress.width == points
between -> H:[VIEW 1]-(51)-[VIEW 2]
Once you understand this, reading your specific error is pretty easy
thanks to http://useYourLoaf.com for this complete solution:
http://useyourloaf.com/blog/using-identifiers-to-debug-autolayout.html
A quick tip I found buried in a WWDC 2015 session on Auto Layout that helps when debugging problems with constraints
If you have used Auto Layout you will be familiar with the log that Xcode spits out when you get something wrong. To create an example I modified my Stack View sample code and added a constraint to each of the images to give them a fixed width of 240 (not a good idea as we will see).
That works in regular width views such as the iPad but is too wide for a compact width view such as the iPhone in portrait. The console log at runtime is not fun to read. Skipping the boilerplate text you get a list of the problematic constraints:
"<NSLayoutConstraint:0x7fc1ab520360 H:[UIImageView:0x7fc1ab532650(240)]>",
"<NSLayoutConstraint:0x7fc1ab536ef0 H:[UIImageView:0x7fc1ab537380(240)]>",
"<NSLayoutConstraint:0x7fc1ab545cc0 UIView:0x7fc1ab53d870.trailingMargin == UIStackView:0x7fc1ab53dae0.trailing>",
"<NSLayoutConstraint:0x7fc1ab545d10 UIStackView:0x7fc1ab53dae0.leading == UIView:0x7fc1ab53d870.leadingMargin>",
"<NSLayoutConstraint:0x7fc1ab54e240 'UISV-alignment' UIStackView:0x7fc1ab53dc70.centerX == UIStackView:0x7fc1ab531a10.centerX>",
"<NSLayoutConstraint:0x7fc1ab5167c0 'UISV-canvas-connection' UIStackView:0x7fc1ab531a10.leading == UIImageView:0x7fc1ab532650.leading>",
"<NSLayoutConstraint:0x7fc1ab54ad80 'UISV-canvas-connection' H:[UIImageView:0x7fc1ab537380]-(0)-| (Names: '|':UIStackView:0x7fc1ab531a10 )>",
"<NSLayoutConstraint:0x7fc1ab5397d0 'UISV-canvas-connection' UIStackView:0x7fc1ab53dae0.leading == _UILayoutSpacer:0x7fc1ab54c3c0'UISV-alignment-spanner'.leading>",
"<NSLayoutConstraint:0x7fc1ab54a4a0 'UISV-canvas-connection' UIStackView:0x7fc1ab53dae0.centerX == UIStackView:0x7fc1ab53dc70.centerX>",
"<NSLayoutConstraint:0x7fc1ab54b110 'UISV-spacing' H:[UIImageView:0x7fc1ab532650]-(16)-[UIImageView:0x7fc1ab537380]>",
"<NSLayoutConstraint:0x7fc1ab548210 'UISV-spanning-boundary' _UILayoutSpacer:0x7fc1ab54c3c0'UISV-alignment-spanner'.leading <= UIStackView:0x7fc1ab531a10.leading>",
"<NSLayoutConstraint:0x7fc1ab551690 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fc1ab53d870(375)]>"
The log then tells you which of the above constraints it has decided to break:
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7fc1ab536ef0 H:[UIImageView:0x7fc1ab537380(240)]>
The log output uses the auto layout visual format language but it is hard to pick out my constraints from those created by the system. This is especially the case with stack views which are by design intended to create most of the constraints for you. In this trivial example I know the fixed width constraints that I just added broke things but it is hard to see that from the log and the more complex the view the harder it gets.
Adding an Identifier to a Constraint
The log gets a lot easier to understand if you add an identifier to each constraint (NSLayoutConstraint has had an identifier property since iOS 7). In Interface Builder find the constraint and add the identifier in the Attributes inspector (I am using $ as a prefix/suffix to make them stand out in the log):
Update 18-August-2015: As pointed out in the comments the identifier can only be edited in Interface Builder starting with Xcode 7. It is not visible in Xcode 6.4.
If adding the constraint in code:
constraint.identifier = "$HeartImageFixedWidth$"
It is trickier if you are using the visual format language which uses arrays of constraints. For example, consider the Swift code fragment to create a fixed width constraint for the heart image view:
let heartWidth = NSLayoutConstraint.constraintsWithVisualFormat("[heart(240)]",
options:[], metrics:nil, views:viewsDictionary)
Since heartWidth is an array of type [NSLayoutConstraint] setting the identifier is a little more work:
for constraint in heartWidth {
constraint.identifier = "$HeartImageFixedWidth$"
}
heartImage.addConstraints(heartWidth)
With identifies set for my constraints it is now much easier to find them in the log file (see the first four lines):
"<NSLayoutConstraint:0x7f92a305aeb0 '$ContainerStackViewLeading$' UIStackView:0x7f92a3053220.leading == UIView:0x7f92a3052fb0.leadingMargin + 32>",
"<NSLayoutConstraint:0x7f92a305b340 '$ContainerStackViewTrailing$' UIView:0x7f92a3052fb0.trailingMargin == UIStackView:0x7f92a3053220.trailing + 32>",
"<NSLayoutConstraint:0x7f92a301cf20 '$HeartImageFixedWidth$' H:[UIImageView:0x7f92a3047ef0(240)]>",
"<NSLayoutConstraint:0x7f92a3009be0 '$StarImageFixedWidth$' H:[UIImageView:0x7f92a304d190(240)]>",
"<NSLayoutConstraint:0x7f92a3060cc0 'UISV-alignment' UIStackView:0x7f92a30533b0.centerX == UIStackView:0x7f92a30472b0.centerX>",
"<NSLayoutConstraint:0x7f92a301c590 'UISV-canvas-connection' UIStackView:0x7f92a30472b0.leading == UIImageView:0x7f92a3047ef0.leading>",
"<NSLayoutConstraint:0x7f92a305f680 'UISV-canvas-connection' H:[UIImageView:0x7f92a304d190]-(0)-| (Names: '|':UIStackView:0x7f92a30472b0 )>",
"<NSLayoutConstraint:0x7f92a3064190 'UISV-canvas-connection' UIStackView:0x7f92a3053220.leading == _UILayoutSpacer:0x7f92a30608a0'UISV-alignment-spanner'.leading>",
"<NSLayoutConstraint:0x7f92a30415d0 'UISV-canvas-connection' UIStackView:0x7f92a3053220.centerX == UIStackView:0x7f92a30533b0.centerX>",
"<NSLayoutConstraint:0x7f92a305fa10 'UISV-spacing' H:[UIImageView:0x7f92a3047ef0]-(16)-[UIImageView:0x7f92a304d190]>",
"<NSLayoutConstraint:0x7f92a30508c0 'UISV-spanning-boundary' _UILayoutSpacer:0x7f92a30608a0'UISV-alignment-spanner'.leading <= UIStackView:0x7f92a30472b0.leading>",
"<NSLayoutConstraint:0x7f92a3063240 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7f92a3052fb0(375)]>"
It also much clearer which of the constraints the system has chosen to break:
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f92a3009be0 '$StarImageFixedWidth$' H:[UIImageView:0x7f92a304d190(240)]>
Adding identifiers to constraints is not without effort but it can pay off the next time you have to sort through the debug log of a complex layout.
Further Reading
WWDC 2015 Session 219 Mysteries of Auto Layout, Part 2
I guess this is not a common error, but I solved it somewhat in a layman way. I was getting cryptic messages like the one above. To make sense of it, I created dummy view classes and attached it to the views in my storyboard. For example, if I had a UIView, I created a class called AddressView and attached it to this view in story board. Its a bit time consuming, but it worked for me. After that instead of object-ids, I got class names which helped me zero in on the views that were causing the issue very easily. My error message now read,
2013-07-02 04:16:20.434 Myproject [2908:c07] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
(
"<NSLayoutConstraint:0x9edeae0 V:|-(0)-[AddressView:0x143ee020] (Names: '|':MainView:0x129eb6a0 )>",
"<NSAutoresizingMaskLayoutConstraint:0x11e998c0 h=--& v=--& V:[MainView:0x129eb6a0(704)]>",
"<NSLayoutConstraint:0x156720b0 V:[AddressView:0x143ee020]-(896)-| (Names: '|':MainView:0x129eb6a0 )>"
)
Here you can see, the names of my views MainView and Address view are causing the issue.
To resolve it, I just moved my subview (in this case Address view) and repositioned it back. I think the issue began as I was using a mix of new Automatic Layour in Xcode 4.5 and old skills or manually positioning the views.
Anyways, not sure if it was more luck than diligence, but nevertheless this could be a different way of debugging. Maybe this helps someone!
YourConstraintView.translatesAutoresizingMaskIntoConstraints = NO;
Did it for me.
I've fixed this problem be deleting all translatesAutoresizingMaskIntoConstraints properties from xib file (Open xib as a source code).
One note. You get this error in logs if you are testing using a personal hotspot connection, and the hotspot status bar is at the top. It throws off the constraints.
Hope this helps someone.. was driving me nuts.
For me this error was spitted when I gave tableView.estimatedRowHeight = UITableViewAutomaticDimension
This should have been tableView.estimatedRowHeight = "Some hardcoded value"
I had this problem and took me 2 days to figure out the source of the problem....
If you open a storyboard programmatically in you code just make sure you do it like this:
UIStoryboard *story = [UIStoryboard storyboardWithName:#"MovieMaker" bundle:nil];
UIViewController *vc = [story instantiateInitialViewController];
//this causes layout to break [self presentViewController:vc animated:YES completion:nil];
[self showViewController:vc sender:nil];
I was using the commented line (using presentViewController) and the orientation bug has happening throwing constraints conflicts that weren't my constraints... changing to showViewController all constraints conflicts were gone and orientation works...... (I don't really know why it works with show and not present... still thinking it's... ALIENS...)
This issue of the generated message "Unable to simultaneously satisfy contraints" in the debug console, is also experienced in XCode 9.4.
In my particular instance on the iPad simulator, the message would generate:
1) Only when placing the focus on a particular UITextField.
2) Even with all view contraints removed.
2) Even with all view contraints "Reset to Suggested Contraints".
However, when the software keyboard was toggled on to display, the message would not be generated.
Therefore, how much time should I spend on this issue, that in my instance is only generated when the software keyboard is toggled off.
this line solved my problem when logs like above in uitableviewCell
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension > CellHeight.rowHeight44 ? UITableView.automaticDimension : CellHeight.rowHeight44
}

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